A heat pipe (tube) is a high performance heat transmission device comprising a tubular member containing a vaporizable fluid in which heat is transferred between hot and cold zones by a continuous cycle of evaporation and condensation of the fluid. When it is functioning properly, a heat pipe can operate with a zero leakage so that it is highly desirable for various applications utilizing corrosive fluids or otherwise requiring high effectiveness and low leakage.
Arrangements that utilize heat pipes have been developed in accordance with U.S. Pat. Nos. 1,725,906 and 2,746,725 wherein heat from a hot fluid is transferred to a cooler fluid flowing adjacent thereto. In all cases it is assumed that each heat pipe in the assembly will maintain its high effectiveness indefinitely. Accordingly there is no provision for detecting inoperative heat pipes or replacing the separate units that may lose their effectiveness because of corrosion or erosion. However, due to corrosion, erosion or other physical damage to the several parts, a heat pipe may become damaged and useless to the extent that it may lose the vaporizable fluid therein and thus lose its effectiveness as a heat exchanger.